package com.tmxk.servlet;

import com.tmxk.bean.NewsBean;
import com.tmxk.dao.NewsDao;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet("/newsfront.html")
public class NewsFrontServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String p = req.getParameter("page");//获取用户传递来的页码
        int page = 1;//默认页码是1
        if (p !=null && p.equals("")){
            page =  Integer.parseInt(p);//字符串转整数
        }
        // 1.获取新闻信息
        NewsDao newsDao = new NewsDao();
        List<NewsBean> news = newsDao.getList(page);
        // 给用户总条数 当前页数 总页数 上一页 下一页
        int totalCount,curPage,totalPage,upPage,downPage;
        totalCount = newsDao.count();//总条数
        curPage = page;//用户传递进来的页码
        if (totalCount%10 == 0){//能除尽 页码不加1
            totalPage = totalCount/10;
        }else {
            totalPage = totalCount/10+1;//计算总页数
        }
        //上一页 当前页数减去1
        if (curPage==1){
            upPage = 1;
        }else {
            upPage  = curPage-1;
        }
        if (curPage==totalPage){//当前页和总页数相同 下一页不+1
            downPage = totalPage;
        }else {
            downPage = curPage+1;
        }
        req.setAttribute("totalCount",totalCount);
        req.setAttribute("curPage",curPage);
        req.setAttribute("totalPage",totalPage);
        req.setAttribute("upPage",upPage);
        req.setAttribute("downPage",downPage);
        // 2.传递新闻信息给前端页面
        req.setAttribute("news",news);
        // 3.加载显示前端页面
        req.getRequestDispatcher("newsFrontList.jsp").forward(req,resp);
    }
}
